Re: [PATCH v2 4/4] drivers: dma-coherent: use memset_io for DMA_MEMORY_IO mappings

From	Andrew Morton <akpm@linux-foundation.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 4/4] drivers: dma-coherent: use memset_io for DMA_MEMORY_IO mappings
Date	2016-03-01 00:20 +0100
Message-ID	<r7FgC-14T-13@gated-at.bofh.it> (permalink)
References	<r7yyu-5hu-25@gated-at.bofh.it> <r7yIa-5le-25@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon, 29 Feb 2016 16:09:24 +0000 Brian Starkey <brian.starkey@arm.com> wrote:

> Use memset_io() for DMA_MEMORY_IO mappings which are mapped as I/O
> memory, and regular memset() for DMA_MEMORY_MAP mappings.
> 
> This fixes the below alignment fault on arm64 for DMA_MEMORY_IO
> mappings, where memset() uses the DC ZVA instruction which is
> invalid on device memory.

What's the urgency of this fix?  "Hair on fire needed in stable asap"
or "Nice to have in there for 4.6" or what?

Thread

[PATCH v2 0/4] Fix kernel panic in dma-coherent allocations Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:10 +0100
  [PATCH v2 1/4] memremap: don't modify flags Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:20 +0100
  [PATCH v2 4/4] drivers: dma-coherent: use memset_io for DMA_MEMORY_IO mappings Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:20 +0100
    Re: [PATCH v2 4/4] drivers: dma-coherent: use memset_io for  DMA_MEMORY_IO mappings Andrew Morton <akpm@linux-foundation.org> - 2016-03-01 00:20 +0100
      Re: [PATCH v2 4/4] drivers: dma-coherent: use memset_io for  DMA_MEMORY_IO mappings Brian Starkey <brian.starkey@arm.com> - 2016-03-01 10:10 +0100
  [PATCH v2 3/4] drivers: dma-coherent: use MEMREMAP_WC for DMA_MEMORY_MAP Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:20 +0100
  [PATCH v2 2/4] memremap: add MEMREMAP_WC flag. Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:20 +0100

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